Superbackscattering Nanoparticle Dimers

TL;DR

This paper presents the theory, optimal design, and practical implementation strategies for superbackscattering nanoparticle dimers, achieving significant backscattering enhancement over single particles through analytical and circuit model approaches.

Contribution

It introduces a theoretical framework and design methodology for maximizing backscattering in nanoparticle dimers, including practical considerations for real materials.

Findings

Electrically small nanoparticle dimers can enhance backscattering by up to 6.25 times.

Optimal configurations can be derived using a simple circuit model.

Fourfold enhancement is feasible with realistic material losses.

Abstract

The theory and design of superbackscattering nanoparticle dimers are presented. We analytically derive the optimal configurations and the upper bound of their backscattering cross-sections. In particular, it is demonstrated that electrically small nanoparticle dimers can enhance the backscattering by a factor of 6.25 with respect to single dipolar particles. We demonstrate that optimal designs approaching this theoretical limit can be found by using a simple circuit model. The study of practical implementations based on plasmonic and high-permittivity particles reveal that fourfold enhancement factors might be attainable even with realistic losses.